We report the study of ultrasound tunneling in 3D phononic crystals, consisting of fcc arrays of close-packed tungsten carbide beads in water. The transmission coefficient, phase velocity, and group velocity were measured along the [111] direction, allowing us to systematically investigate the tunneling of ultrasound at frequencies in the lowest band gap. Our experimental data are interpreted u...

A series of supported WO3 catalysts were synthesized by incipient wetness impregnation of ammonium metatungstate aqueous solutions onto Al2O3, TiO2, Nb2O5, and ZrO2 supports as a function of tungsten oxide loading. The resulting solid acid catalysts were physically characterized with in situ Raman and UV–vis spectroscopy and chemically probed by methanol dehydration to dimethyl ether (CH3OH-TPS...

Theoretical studies of tungsten ions in plasmas are presented. New calculations of the radiative recombination and photoionization cross-sections, as well as radiative recombination and radiated power loss rate coefficients have been performed for 54 tungsten ions for the range W–W. The data are of importance for fusion investigations at the reactor ITER, as well as devices ASDEX Upgrade and EB...

Exposure to metals may promote atherosclerosis. Blood cadmium and lead were associated with peripheral arterial disease (PAD) in the 1999-2000 National Health and Nutrition Examination Survey (NHANES). In the present study we evaluated the association between urinary levels of cadmium, lead, barium, cobalt, cesium, molybdenum, antimony, thallium, and tungsten with PAD in a cross-sectional analy...

The origin of spin-orbit torques, which are generated by the conversion of charge-to-spin currents in non-magnetic materials, is of considerable debate. One of the most interesting materials is tungsten, for which large spin-orbit torques have been found in thin films that are stabilized in the A15 (β-phase) structure. Here we report large spin Hall angles of up to approximately -0.5 by incorpo...

Tungsten-containing amorphous carbon films were produced by dual magnetron sputter deposition. The formation of carbide phases after heat treatment in inert gas at temperatures up to 2800 K was investigated by X-ray diffraction for tungsten concentrations below 25 at%. After deposition, each film consists of an amorphous carbon matrix with atomically dispersed W inclusions. Annealing up to 2800...

A chemistry-based approach to designing precursors for the deposition of inorganic films requires consideration of the physical properties of the precursor compound (e.g., volatility for transport in the reactor) and its probable decomposition pathways, both in the gas phase and on the surface during growth. We have been using Aerosol-Assisted Chemical Vapor Deposition of tungsten carbonitride ...

Tungsten doped amorphous carbon films are prepared on silicon 100 by postimplantation of tungsten ions into pure amorphous hydrogenated carbon using the plasma immersion ion implantation technique. The peak concentration of tungsten reaches 27 at. % and W–C nanocrystallites with largest diameters of 5 nm are formed in the near surface region. Both the quantity and size of these nanocrystallites...

The use of a liquid metal jet [1] as the primary target at a muon collider source is not yet an established technique. Among possible alternatives, we are investigating the use of a jet of tungsten powder. We first considered metal-powder slurries, based on the example of a commercial zinc paint with density 3 g/cm. For a muon collider target, both high atomic number and high density are desira...

We report a molecular dynamics simulation of melting of tungsten (W) nanoparticles. The modified embedded atom method (MEAM) interatomic potentials are used to describe the interaction between tungsten atoms. The melting temperature of unsupported tungsten nanoparticles of different sizes are found to decrease as the size of the particles decreases. The melting temperature obtained in the prese...